1. Technical Field
The present invention relates generally to integrated circuits having fuse elements, and more particularly, to a laser fuse deletion process.
2. Related Art
Fuses formed within integrated circuits serve several functions. For example, fuses may be formed within a circuit to provide redundancy. In other words, particular fuses may be deleted or opened to re-route circuitry along alternate pathways in the event of a failure. Alternatively, fuses may be selectively deleted to form a matrix of opens and shorts unique to that circuit which may easily be recognized by an electrical computer identification system.
Laser fusing processes are typically used to delete specific fuses. During a laser fuse deletion process the fuse structure, including the size, shape and material of the fuse itself, as well as the type and thickness of the material covering the fuse, are of critical importance to the quality of the fuse deletion. Accordingly, it is desirable to optimize any or all of these parameters to enhance the success of the fuse deletion process.
The first general aspect of the present invention provides a semiconductor device comprising: a substrate; at least one fuse formed within the substrate; and an etch resistant layer over at least one of the formed fuses.
The second general aspect of the present invention provides a method of forming a fuse structure, comprising: providing a substrate having at least one fuse formed therein; and depositing an etch resistant layer over a surface of the substrate.
The third general aspect of the present invention provides a method of performing a fuse deletion process, comprising: providing a substrate having at least one fuse therein, an etch resistant layer over the fuse and at least one insulative layer over the etch resistant layer; removing a portion of the at least one insulative layer above the fuse to the etch resistant layer; and applying a radiant energy source to the fuse until the etch resistant layer is partially removed.
The foregoing and other features and advantages of the invention will be apparent from the following more particular description of the embodiments of the invention.